The present invention relates generally to the field of locks, and more particularly to an electrically energizable power actuator unit for operating a high security lock bolt of the cam actuated type.
Heretofore, cam actuated locking mechanisms have for the most part been arranged for manual actuation by means of an appropriate key. Locks of this type are generally disclosed, for example, in Eads U.S. Letters Pat. No. 2,989,859, issued Jan. 27, 1961. In the lock mechanism of this patent, provision is made for operation of the bolt by means of a 360.degree. rotatable cam connected with the key cylinder actuator, this cam being connected for operation of a bolt actuating lever, rather than directly operating the bolt which in this case is pivotally mounted for swinging movements between locking and non-locking positions. The actuator of the present invention, however, is not to be considered as being limited to the particular lock structure as disclosed in this patent.
More recently, efforts have been made to provide electric power actuators for locks of the above described high security type, and which would be compatible with and permit their being used in connection with the now available sophisticated electronic lock controlling systems of the type utilizing keyed cards, coded push-button systems, proximity switches, and the like.
Having in mind that electric solenoids have long been successfully used for the actuation of certain types of locks and latches, which in the main required only a relatively low power or relatively small bolt or latch movements; attempts were first made to use a solenoid as the power actuating medium. It was found that the use of solenoids presented operation problems when used with a high security type of lock, such as disclosed in the above mentioned Eads Patent. It was found that the solenoid lacked the necessary controlability, power, and in particular the necessary motion or stroke required for the operation of the high security locking mechanism.
Accordingly, the design was changed to include an electric motor driven mechanism, in lieu of a solenoid operable mechanism. The electric motor drive overcomes the inherent problems of the solenoid, and in the present invention has been utilized in combination with a manually operable override to provide a unique actuating unit which may be mounted on the door frame for actuating a high security locking mechanism of the high security type as described above, and yet an actuating unit which is adapted for operation in connection with the great variety of currently available electronic control systems.